Polymer stabilized vertical alignment (PS-VA) is a technology of thin film field-effect transistor of liquid crystal display (LCD) device. In a cell manufacturing process of PS-VA, reactive monomers are included among liquid crystals, and therefore there is a procedure of liquid crystal curing. As shown in FIG. 1, reactive monomers included among liquid crystals react by irradiating a substrate with ultraviolet light, so that the liquid crystals can have a pretilt angle. Such a procedure is called ultraviolet light alignment.
During a course of ultraviolet light alignment, a size of the pretilt angle formed by liquid crystals would directly affect subsequent optical characteristics of a panel. When the pretilt angle is too small, the panel would have a very long response time. When the pretilt angle is too large, the panel would have very low contrast. Therefore, a proper pretilt angle needs to be formed for the panel in production.
In actual production, large substrate production is generally adopted, i.e., a plurality of panels can be distributed on one large substrate. As shown in FIG. 2, in order to facilitate design and manufacture, a plurality of panels arranged on a large substrate generally have a same size. Since a large substrate has a fixed size, in production, when products with a certain size are arranged on the substrate, a large empty space would be left on the substrate, which results in a low utilization rate of the substrate. Therefore, at present, products based on multi-model glass technology (NMG) are developed in the industry. As shown in FIG. 3, in such a manufacturing manner, products with different sizes are arranged on a large substrate at the same time, so that there can be a minimum empty space on the substrate at the same time, thereby realizing a maximum utilization rate of the substrate.
In actual production, an ultraviolet light intensity and a stage temperature within a stage are uniform. With respect to a traditional production manner, panels on a substrate all have a same size, and therefore the panels are designed in a same way and have a same aperture rate. Therefore, ultraviolet light intensities received by reactive monomers in respective panels on the substrate are same, and a same pretilt angle can be formed in the panels.
With respect to MMG products, since panels on a substrate have different sizes, the panels of different sizes are designed in different ways and have different aperture rates. Therefore, when ultraviolet light alignment is performed in a stage, ultraviolet light intensities received by reactive monomers in the panels of different sizes are different. Therefore, products of different sizes have different pretilt angles at last, which leads to a result that properties of the products of different sizes cannot reach standards thereof at the same time.